public class ComputerAver extends DoThing {
   DoThing nextDoThing ;
   public void setNext(DoThing next) {
      nextDoThing = next;
   }
   public void doThing(double [] a) {
      double sum = 0;
      for(int i=0;i<a.length;i++)
          sum = sum+a[i];
      double aver = sum/a.length; 
      System.out.print("选手最后得分"+aver);
   }
}